Oddly, warm water cools you down: it widens blood vessels in your hands and feet, which then shed heat and speed up the drop in core temperature that triggers sleep. A meta-analysis found that a warm bath or shower one to two hours before bed cuts the time to fall asleep by around ten minutes. Timing is everything.
Chlorine on its own is fairly gentle. But when it combines with urine, sweat and other grime from swimmers, it forms chloramines, which cause stinging eyes and that classic 'chlorine smell'. A well-kept pool barely smells at all. Shower before you swim and never pee in the water.
Muscle mass slowly shrinks with age, putting independence at risk. But in 1990, a study had nursing home residents aged 86 to 96 train their legs for eight weeks: their strength more than doubled. Muscle responds to training at any age. Getting up from a chair without using your hands is already an exercise.